In recent years, the concept of minimally invasive surgery has become accepted by the surgical community, though there are limitations in locating small gastrointestinal tumors when laparoscopy is used alone. Meanwhile, endoscopy is an excellent tool for locating these small tumors, though one must take extreme care to avoid hollow viscus perforation. Combination of laparoscopy and gastroduodenoscopy has extensive application in the resection of gastrointestinal stromal tumors, sessile gastric polyps and early gastrointestinal carcinoma. During laparoscopic operation, the endoscopist can help to locate the tumor or polyp. Endoscopy can also help to determine whether or not the tumor or polyp has been resected completely. In performing traditional laparoscopic colectomy for left-sided colonic tumors, specimen retrieval necessitates a mini-incision which is often the cause of postoperative pain, wound infection, and other pain-related complications. The combination of laparoscopy with transanal endoscopic microsurgery is feasible for selected patients with left-sided colonic tumors, and complications related to mini-incision can be avoided completely. Combination of laparoscopy and gastrointestinal endoscopy also benefits patients with acute bowel obstruction prior surgical operation. With the help of perineum-bowel tube, sigmoidoscopic technique can relieve acute bowel obstruction, so that these patients may have chance for laparoscopic operation. In summary, this hybrid approach can not only decrease surgical incisions, but also avoid some of the surgical risks of emergent operations.

Objective To investigate the efficacy and toxicity of neoadjuvant chemotherapy of modified FOLFOX7 regimen in the treatment of advanced gastric cancer. Methods The clinical data of 30 patients with advanced gastric cancer who had been admitted to Beijing Friendship Hospital from June 2005 to January 2009 were retrospectively analyzed. All patients received modified FOLFOX7 regimen [oxaliplatin (100 mg/m~2) + fluorouracil (2400 mg/m~2) + calcium folinate (400 mg/m~2)] for 2-4 courses before operation. The efficacy and toxicity of the modified FOLFOX7 were evaluated before and after the operation. All data were analyzed via chi-square test. Results The pre-and postoperative downstaging rates were 27% (8/30) and 47% (14/30), respectively. The total effective rate of modified FOLFOX7 regimen was 43% (13/30). Complete remission was observed in 1 patient. The toxicity was mild. Radical resection was accomplished in 28 patients (93%). There was no statistical difference between the 2 criteria in evaluating the efficacy of modified FOLFOX7 regimen (χ~2= 2.584, P>0.05). Conclusion Modified FOLFOX7 regimen is effective and well-tolerable for patients with advanced gastric cancer.

OBJECTIVETo verify the clinical safety of complete mesocolic excision (CME) and manufacture pathological large slices.

METHODSA prospective analysis clinical data of 85 right colon cancer in patients by the same group of surgeons at the Department of General Surgery, Beijing Friendship Hospital, Capital Medical University from January 2012 to December 2013 which were divided into two groups: CME group (n=39) and traditional radical operation group (n=46) by surgical approach. CME group and control group were compared the differences of clinic and pathologic variables, precise tissues morphometry, lymph nodes harvest, mesocolic area and so on. By comparison to operation time, blood loss, postoperative complications, flatus restoring time, drainage removal time and length of stay, the security of CME was analyzed. Statistical methods included independent sample t-test, Wilcoxon rank sum test and χ(2) test. In order to manufacture pathological large slices, the CME operation specimens were fixed. The large slices were stained by routine HE staining to detection of circumferential resection margin.

RESULTSMean number of total lymph nodes was increased obviously in CME group (26.8±1.9 vs. 23.2±3.4, t=4.261, P=0.000). Mean number of lymph nodes of stage Ⅰ, Ⅱ were different between two groups (25.8±3.6 vs. 18.2±4.5, 26.8±7.7 vs. 24.9±6.2, t=8.776, 2.802, P=0.000). The positive lymph nodes of CME group was higher than control group (4(7) vs. 1.5(2), P=0.032), above all with statistically significant difference. Comparing CME group with the control group, there were the larger area of mesentery ((15 555±1 263) mm(2) vs. (12 493±1 002) mm(2,) t=12.456, P=0.000), the greater distance between the tumor and the high vascular tie ((116±22) mm vs. (82±11) mm, t=9.295, P=0.000), the greater distance between the normal bowel and the high vascular tie ((92±17) mm vs. (74±10) mm, t=8.132, P=0.000) of CME, with statistically significant difference. There were no statistically significant differences from operation safety when CME group was compared with the control group. The pathological large slices of colon cancer were prepared successfully and dyed evenly than those large slices were used to observe whether the lymph tube and lymph node metastasis inside the mesocolon. Existence of direct tumor invasion could be confirmed by investigating the large slices. Cancer embolus in intravascular and micro infiltration in mesocolon also could be found.

CONCLUSIONSCME operation can get the standard excision according the mesocolic area and integrity, as well as to harvest the maximum number of lymph node. The clinical application of CME is safe and does not increase the risk of operation. Circumferential resection margins can be detected by pathological large slices.

Colectomy ; Colonic Neoplasms ; surgery ; Device Removal ; Humans ; Lymph Node Excision ; Lymph Nodes ; Lymphatic Metastasis ; Mesocolon ; surgery ; Operative Time ; Postoperative Complications ; Prospective Studies

Objective To explore the clinicopathological features and prognosis of the obstructive colorectal cancer (CRC).Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 667 CRC patients who were admitted to the Beijing Friendship Hospital Affiliated to Capital Medical University between January 2013 and December 2015 were collected.The diagnosis and treatment of CRC patients were based on colon cancer and rectal cancer clinical practice guidelines in oncology(Version 2013) of the National Comprehensive Cancer Network (NCCN) and the 7th edition of the American Joint Committee on Cancer (AJCC) cancer staging manual and the future of TNM.CRC and clinical staging were confirmed by colonoscopy,biopsy pathology and CT or MRI examination.Patients selected laparoscopic surgery or open surgery according to their conditions,and then selectively underwent postoperative adjuvant therapy based on the results of pathological examination.Observation indicators:(1) diagnosis and treatment;(2) clinicopathological features;(3) prognosis.Follow-up using outpatient examination and telephone interview was performed to detect postoperative overall and tumor-free survivals up to April,2017.Measurement data with normal distribution were represented as (x)±s and comparison between groups was analyzed using the t test.Count data were described as case and percentage,comparisons between groups were evaluated with the chi-square test.Ordinal data were analyzed using the nonparametric test.Results (1) Diagnosis and treatment:tumor locations of 677 patients:tumors located in the right hemicolon,left hemicolon and rectum were respectively detected in 213,312 and 142 patients.Preoperative clinical staging:3,47,300,298 and 19 patients were respectively detected in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ.Ninety-nine patients were complicated with intestinal obstruction,with an obstructive rate of 14.84％ (99/667),and 568 patients didn't have intestinal obstruction.Treatments of 667 patients:① Preoperative adjuvant treatment:17 non-obstructive CRC patients underwent preoperative adjuvant treatments and 650 didn't undergo preoperative adjuvant treatment.② Surgical treatment:389 and 278 patients underwent respectively open and laparoscopic surgeries,and 588 received radical resection and 79 received non-radical resection.(2) Clinicopathological features:of 99 obstructive CRC patients,tumors located in the right hemicolon,left hemicolon and rectum were respectively detected in 26,61 and 12 patients.Eighteen and 81 patients underwent respectively laparoscopic and open surgeries,including 21 with low-differentiated tumors,61 with moderate-differentiated tumors and 17 with high-differentiated tumors;71 patients received radical resection,with a number of lymph node dissected of 12±9,and 37,20 and 14 were respectively detected in stage N0,N1 and N2.Of 568 non-obstructive CRC patients,tumors located in the right hemicolon,left hemicolon and rectum were respectively detected in 187,251 and 130 patients.Two hundred and sixty and 308 patients underwent respectively laparoscopic and open surgeries,including 38 with low-differentiated tumors,420 with moderate-differentiated tumors and 110 with high-differentiated tumors;517 patients received radical resection,with a number of lymph node dissected of 15±8,and 338,155 and 24 were respectively detected in stage N0,N1 and N2.There were statistically significant differences in above indicators between obstructive CRC and non-obstructive CRC patients(x2=11.234,46.505,30.088,Z=-2.782,t=2.942,Z=-2.892,P＜0.05).(3) Prognosis:of 667 patients,584 were followed up for 18-52 months,with a median time of 36 months,including 88 with obstructive CRC (1,5,23,28 and 31patients were respectively in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ) and 469 with non-obstructive CRC (5,62,212,116 and 101 patients were respectively in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ).During the follow-up,56 obstructive CRC patients survived,including 1 in stage 0,4 in stage Ⅰ,15 in stage Ⅱ,17 in stage Ⅲ and 19 in stage Ⅳ,with an overall survival rate of 63.64％ (56/88),and overall survival rates in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ were respectively 1/1,4/5,65.22％(15/23),60.71％(17/28) and 61.29％ (19/31);38 had tumor-free survival,including 1 in stage 0,4 in stage Ⅰ,15 in stage Ⅱ,13 in stage Ⅲ and 5 in stage Ⅳ,with a tumor-free survival rate of 43.18％(38/88),and tumor-free survival rates in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ were respectively 1/1,4/5,65.22％ (15/23),46.43％ (13/28),16.13％ (5/31).Four hundred and forty-three non-obstructive CRC patients survived,including 5 in stage 0,58 in stage Ⅰ,181 in stage Ⅱ,106 in stage Ⅲ and 93 in stage Ⅳ,with an overall survival rate of 89.31％(443/496),and overall survival rates in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ were respectively 5/5,93.55％ (58/62),85.38％ (181/212),91.38％ (106/116) and 92.08％ (93/101);384patients had tumor-free survival,including 5 in stage 0,52 in stage Ⅰ,166 in stage Ⅱ,94 in stage Ⅲ and 67 in stage Ⅳ,with a tumor-free survival rate of 77.42％ (384/496),and tumor-free survival rates in stage 0,Ⅰ,Ⅱ,Ⅲ and Ⅳ were respectively 5/5,83.87％ (52/62),78.30％ (166/212),81.03％ (94/116) and 66.34％ (67/101).There were statistically significant differences in overall survival rate and tumor-free survival rate between obstructive CRC and non-obstructive CRC patients (x2 =39.626,43.707,P＜ 0.05).The subgroup analysis:there were statistically significant differences in stage Ⅱ,Ⅲ and Ⅳ overall survival rates between obstructive CRC and non-obstructive CRC patients (x2 =6.092,17.027,11.268,P＜0.05) and in stage Ⅲ and Ⅳ tumor-free survival rates (x2 =14.148,24.116,P＜ 0.05).Conclusion The obstructive CRC commonly locates in the left hemicolon,with complex clinicopathological features and low-differentiated tumors,meanwhile,there are lower radical rate and poor prognosis.

Objective To explore the effect of transanal total mesorectal excision (TaTME) structured training on the operation of frozen cadaver specimens in mainland China.Methods The retrospective crosssectional study was conducted.The data of 9 trainees who participated in the 1st TaTME structured training between April 12 and 13,2018 were collected.Chinese Society of Colorectal Surgery,Chinese Society of TaTME Surgeons and Beijing Anatomy Society were the host of TaTME structured training,Beijing Friendship Hospital of Capital Medical University and Clinical Applied Anatomy Science and Technology Training Center of Beijing Society for Anatomy Society were the undertakers.The courses included theoretical teaching,operation demonstration and frozen cadaveric specimens operation.Nine trainees were allocated into the 3 groups,including trainees A,C,E in group 1,trainees B,D,F in group 2 and trainees G,H,I in group 3.The special questionnaire survey was carried out on all the trainees at 3 months after the end of the training,contents included the number and proficiency of TaTME before and after training,reasons for not performing TaTME,learning curve of TaTME,TaTME-related complications and adverse reactions,whether or not to continue TaTME in future,effects of training,whether or not necessary to take training before TaTME.Observation indicators:(1) situations of trainees taking part in theoretical lectures and operation demonstration;(2) situations of trainees taking part in frozen cadaveric specimens operation;(3) questionnaire survey situations of trainees at 3 months after training.Comparison of trainees before and after training was done by the rank-sum test.Results (1) Situations of trainees taking part in theoretical lectures and operation demonstration:9 trainees received theoretical lectures and operation demonstration.The theoretical lectures helped deepen understanding of the TaTME,and operation demonstration gave an intuitive feel of technical points and considerations for TaTME.(2) Situations of trainees taking part in frozen cadaveric specimens operation:9 trainees performed successfully frozen cadaveric specimens operation under the guidance of the instructors to achieve training purposes.Overall evaluation of the instructors:anastomotic stoma was intact in 3 groups;grading 2 of Quirke grading of mesorectum was detected in group 1 and 2,and grading 3 in group 3;the main difficulty of complications was incorrect interstice operation and poor smog control,and urethral injury occurred in group 3.(3) Questionnaire survey situations of trainees at 3 months after training:2,2,2 and 3 trainees after training carried respectively on more than 10,6-10,1 and 0 times TaTME,2,2,1 and 4 trainees before training carried respectively on 6-10,2-5,1 and 0 in number of TaTME before and after training,with no statistically significant difference (Z =1.000,P＞ 0.05).Three trainees didn't perform TaTME due to no suitable patient,no equipment for TaTME and incompletely master operating of TaTME.After training,1 trainee was very proficient for TaTME,3,3 and 2 trainees respectively needed to 1/4,1/2 and 3/4 of guidance;before training,1,4 and 3 trainees needed to respectively 1/4,1/2 and 3/4 of guidance,and 3 trainees were very inaptitude for TaTME,with no statistically significant difference in proficiency of TaTME before and after training (Z=1.243,P＞0.05).Five of 9 trainees thought that finishing learning curve needed 10 times TaTME.TaTME-related complications and adverse reactions included urethral injury,bleeding,incorrect interstice operation and incomplete specimens.Eight of 9 trainees expressed that would continue to carry on TaTME.All trainees thought TaTME structured training was very necessary and training should be finished before TaTME.Conclusions The TaTME structured training program on the operation of frozen cadaver specimens is a new attempt.The structured and standardized TaTME training is a necessary condition for clinical performing of TaTME,which is conductive to improving the safety and effectiveness of TaTME.

Objective:To investigate the relationship between systematic immune-inflamma-tion index(SII) and clinicopathological characteristics for colorectal cancer.Methods:The retrospec-tive cohort study was conducted. The clinicopathological data of 513 patients with colorectal cancer who were admitted to the Beijing Friendship Hospital of Capital Medical University from February 2019 to May 2021 were collected. There were 311 males and 202 females, aged (64±12)years. Observation indicators: (1) SII of colorectal cancer and relationship between SII and clinicopatholo-gical characteristics; (2) influencing factors for SII in colorectal cancer patients. According to the median of SII as the cutoff value, the patients were divided into high SII and low SII patients. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Count data were represented as absolute numbers or percen-tages, and comparison between groups was conducted using the chi-square test. Measurement data with skewed distribution were represented as M( P25, P75), and comparison between groups was analyzed using the non-parameter rank sum test. Comparison of ordinal data was analyzed using the Mann-Whitney U non-parameter test. Variables with statistically significant differences between groups were included for further analysis. Pearson correlation coefficient analysis was used for continuous data, and Wilcoxon or Kruskal-Willas analysis was used for categorical data and Bonferroni correction was performed. Univariate and multivariate linear regression analyses were conducted. Results:(1) SII of colorectal cancer and relationship between SII and clinicopathological charac-teristics: the SII of 513 patients was 355(253,507). Taking the median SII 355 as the cutoff value, 257 of 513 patients with SII>355 had high SII and 256 cases with SII≤355 had low SII. Of high SII patients, the Karnofsky performance status(KPS) score, preoperative albumin(Alb), CA125, cases with tumor located at left or right hemicolon, tumor diameter, cases with laparoscopic assisted surgery or laparotomy (surgical approach), cases in stage T0, T1, T2, T3, T4 (pathological T staging), cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ (pathological TNM staging) were 87±17, (37±5)g/L, 8.80 U/mL(5.90 U/mL, 14.15 U/mL), 174, 83, (5.2±2.8)cm, 208, 44, 5, 19, 25, 131, 63, 34, 98, 94, 14. The above indicators of low SII patients were 91±13, (38±4)g/L, 7.20 U/mL(5.40 U/mL, 10.03 U/mL), 200, 56, (4.0±1.9)cm, 221, 24, 8, 39, 35, 118, 45, 61, 84, 79, 12. There were significant differences in above indicators between the two groups ( t=-2.770, -3.211, Z=-3.799, χ2=7.050, t=5.324, χ2=6.179, Z=-3.390, -2.227, P<0.05). Results of Pearson correlation coefficient analysis showed that SII was positively correlated with the tumor diameter ( r=0.390, P<0.05), and negatively correlated with preoperative Alb ( r=-0.200, P<0.05). Results of Wilcoxon analysis showed that SII was 447(311,720), 352(251,493) in patients with tumor located at right hemicolon and left hemicolon, 439(284,640), 345(243,481) in patients undergoing laparotomy and laparoscopic assisted surgery, respectively. There were signi-ficant differences in SII between patients with tumor located at right and left hemicolon,between patients undergoing laparotomy and laparoscopic assisted surgery ( P<0.05). Results of Kruskal-Willas analy-sis showed that SII was 289(201,463), 296(210,398), 329(252,446), 369(265,505), 434(274,631) in patients with pathological T staging as stage T0, stage T1, stage T2, stage T3, stage T4, respectively, and 307(226,400), 380(260,503), 381(272,563), 376(273,634) in patients with patho-logical TNM staging as stage Ⅰ, stage Ⅱ, stage Ⅲ, stage Ⅳ, respectively. There were significant differences in SII between patients with different pathological T staging and between patients with different pathological TNM staging ( P<0.05). (2) Influencing factors for SII in colorectal cancer patients: results of univariate analysis showed that KPS score, preoperative Alb, CA125, tumor location, tumor diameter, patholo-gical N staging, pathological TNM staging were related factors for SII in colorectal cancer patients ( Beta=-3.5, -15.8, 3.7, 106.3, 51.8, 115.1, 104.7, 141.2,95% confidence interval as -5.7 to -1.3, -22.6 to -9.1, 1.8 to 5.5,34.6 to 177.9, 38.5 to 65.2, 40.5 to 189.7, 11.2 to 198.2, 46.9 to 235.9, P<0.05). Multivariate analysis showed that tumor location and tumor diameter were independent influencing factors for SII in colorectal cancer patients ( Beta=79.5, 42.5, 95% confidence interval as 8.4 to 150.7, 26.6 to 58.4, P<0.05). Conclusions:The SII is correlated with tumor location, tumor diameter, preoperative Alb, pathological T staging, pathological TNM staging. Preoperative hypoproteinemia indicates a high SII score. The longer of tumor diameter, right hemicolon tumor and high TNM staging indicate the more serious immune-inflammatory imbalance. Tumor location and tumor diameter are independent influencing factors for SII in colorectal cancer patients.

Objective:To investigate the effect of obstruction on the prognosis and possible mechanisms in colorectal cancer patients.Methods:Among 1574 cases of colorectal cancer who were treated in Beijing Friendship Hospital, Capital Medical University from January 2003 to December. 2014, 194 cases had preoperative intestinal obstruction. Firstly, described the clinical characteristics of 194 patients with obstruction, then COX multivariate regression analysis was performed on the 1574 colorectal cancer cohort to confirm whether the preoperative obstruction was independent predictor for the overall survival. Finally, propensity score matching method was used to match obstruction and non-obstruction cases, then compared overall survival difference.Results:In 194 cases of obstructive colorectal cancer, 60.3% and 37.1% of the tumors were located in the left and right respectively. The 55.7% of the patients had tumors larger than 5 cm in diameter, the median survival time was 39.7 months (95% CI: 28.3-60.4). Multivariate COX analysis, after adjusted for related confounding factors, found that preoperative obstruction is still an independent risk factor for poor prognosis ( HR=1.41, 95% CI: 1.01-1.97). After propensity score matching, 140 and 560 patients were included in the obstructive group and the non-obstructive group. The two groups were more balanced in most baseline characteristics. The median survival time of the two groups was 42.4 and 116.3 months ( P<0.001), the overall survival of obstructive patients was significantly worse than that of non-obstructive patients. Conclusions:Preoperative obstruction is an independent risk factor for poor prognosis of colorectal cancer. This may be due to the difficulty of surgery and low radical cure rate for obstructive colorectal cancer.

Objective:To analyze the negative effect of prolonged postoperative ileus on postoperative recovery in patients underwent open alimentary tract surgery.Methods:This study was a retrospective cohort study. The subjects of the study were patients who underwent open gastrointestinal surgery at the General Surgery Department of Beijing Friendship Hospital, Capital Medical University from October 2016 to November 2018. According to the PPOI diagnostic criteria proposed by the University of Auckland, the included patients were classified as PPOI Group ( n=14) and non-PPOI group ( n=112). The postoperative complications, postoperative hospital stay and medical expenses during hospitalization were selected as the study endpoint indicators. T-test or Fisher′s exact test were performed to compare the differences between the two groups, and linear regression analysis was used to explore the independent effects of PPOI on hospital stay and medical expenses. Results:The incidence of PPOI in this study cohort was 11.1%. The total postoperative complications occurred more frequent in PPOI group (64.29% vs 38.39%, P=0.08). The average postoperative hospital stay of patients in the PPOI group was longer than that in non-PPOI group [(21.21±14.83) d vs (13.98±14.21) d, P=0.070]. Adjusting for various possible confounding factors, the PPOI regression coefficient beta (95% CI) that affects the length of hospital stay was [-0.43 (-7.16, 6.3), P=0.90]. The average medical cost of patients in the PPOI group was more than that in non-PPOI group [(104 389.64±52 427.66)元比(79 111.41±50 832.29)元, P=0.070]. Adjusting for various possible confounding factors, the PPOI regression coefficient beta (95% CI) that affects medical expenditure was [-134.12 (-21656.85, 21388.62), P=0.99]. Conclusions:Prolonged postoperative ileus leads to delayed postoperative recovery, which is related to increased postoperative complications, hospital stay duration and medical cost. But it needs further confirmation from large sample data.

Objective:To explore the practical application and clinical significance of modified grading system for Gastrointestinal Symptom Rating Scale (GSRS) scores in evaluating long-term postoperative gastrointestinal dysfunction (PGID) in patients after colon cancer surgery.Methods:A retrospective analysis was conducted on the case data of 122 patients who underwent right hemicolectomy for colorectal cancer at Beijing Friendship Hospital, Capital Medical University from September 2021 to September 2022. Among these patients, 69 were males (56.6%), and 53 were females (43.4%). The median age was 66.5 years, and the body mass index was (24.4±3.3) kg/m 2. The main observe indiator was GSRS scores of patients. The measurement data of normal distribution were represented as mean±standard deviation( ± s), and intergroup comparisons were conducted using ANOVA. The measurement data of non-normal distribution were expressed as the median (interquartile distance) [ M( Q1, Q3)], the Kruskal-Wallis H test was employed. Unordered count data comparisons were performed using the χ2 test, while comparisons for ordered count data between groups were conducted using the Kruskal-Wallis H test. GSRS scores were represented using density plots, and the scores were categorized into five symptom groups, presented using radar charts to illustrate the distribution of each symptom group. Results:Among the 122 patients, the most common long-term PGID syndromes was dyspepsia, followed by abdominal pain, diarrhea, and constipation. GSRS score data in the study population exhibited a nearly trimodal trend. Based on the overall data trend, the GSRS scale was refined, with cut-off values of 20 and 30, categorizing patients with right-sided colon cancer into low-risk, moderate-risk, and high-risk groups for quantifying the severity of long-term PGID. In terms of gender distribution, the differences among the three groups was statistically significant ( P=0.031), suggesting that males may be more susceptible to long-term PGID. However, there were no significant differences among the three groups concerning age, tumor location, surgical approach, anastomotic technique, lymph node dissection, pathological staging, adjuvant chemotherapy, and other factors. Conclusions:The modified grading system for GSRS scores aligns with the distribution characteristics of postoperative gastrointestinal function in colorectal cancer patients. It can quantify the risk of long-term PGID, allowing for a graded management approach to improve the postoperative quality of life for patients.

Objective:To investigate the incidence and influencing factors of anastomotic leakage after anterior resection (AR) for rectal cancer.Methods:The retrospective case-control study was conducted. The clinicopathological data of 1 243 patients with rectal cancer who were admitted to 3 medical centers between August 2008 and July 2017 were collected, including 512 in the Beijing Friendship Hospital of Capital Medical University, 480 in the Cancer Hospital of Chinese Academy of Medical Sciences, 251 in the Peking University People′s Hospital. There were 734 males and 509 females, aged from 25 to 89 years, with an average age of 65 years. All patients underwent AR for rectal cancer. Observation indicators: (1) surgical situations and incidence of postoperative anastomotic leakage; (2) influencing factors for postoperative anastomotic leakage. Measurement data with skewed distribution were represented as M (range). Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Univariate analysis was conducted using the chi-square test. Multivariate analysis was conducted using the Logistic regression model based on factors with P<0.10 in the univariate analysis. Results:(1) Surgical situations and incidence of postoperative anastomotic leakage: all the 1 243 patients with rectal cancer underwent successfully AR including 219 undergoing defunctioning stoma and 1 024 undergoing non-defunctioning stoma, of which 70 patients had postoperative anastomotic leakage, with a total incidence rate of 5.632%(70/1 243). The incidence rates of grade A anastomotic leakage, grade B anastomotic leakage, and grade C anastomotic leakage were 27.1%(19/70), 21.4%(15/70), 51.4%(36/70), respectively. (2) Influencing factors for postoperative anastomotic leakage: results of univariate analysis showed that gender, surgical procedure, volume of intra-operative blood loss, and pathological metastasis staging were related factors for anastomotic leakage after AR ( χ2=8.518, 6.548, 10.834, 4.501, P<0.05). Results of multivariate analysis based on factors with P<0.10 in the univariate analysis showed that male and volume of intraoperative blood loss≥100 mL were independent risk factors for anastomotic leakage after AR [ odds ratio ( OR)=2.250, 1.949, 95% confidence interval ( CI): 1.281-3.952, 1.142-3.324, P<0.05)]; defunctioning stoma was an independent protective factor for anastomotic leakage after AR ( OR=0.449, 95% CI: 0.201-1.001, P<0.05). Subgroup analysis on effects of defunctioning stoma versus non-defunctioning stoma on grade of anastomotic leakage showed that percentage of grade C anastomotic leakage for defunctioning stoma group was 14.3%(1/7), versus 55.6%(35/63) for non-defunctioning stoma group, with a significant difference between the two groups ( χ2=9.570, P<0.05). Conclusions:Male and volume of intraoperative blood loss≥100 mL are independent risk factors for anastomotic leakage after AR. Defunctioning stoma is an independent protective factor for anastomotic leakage after AR. For male patients and patients with large volume of intraoperative blood loss, defunctioning stoma is recommended to reduce the incidence of postoperative anastomotic leakage.